Lighting devices with automatic lighting adjustment

ABSTRACT

Lighting systems and associated controls that can provide active control of lighting device settings, such as on/off, color, intensity, focal length, beam location, beam size and beam shape. In some examples, lighting systems may include eye tracking technology and sensor feedback for one or more lighting device settings and may be configured with depth perception and cavity or incision recognition capability through image or video processing.

FIELD OF THE DISCLOSURE

The present disclosure generally relates to the field of lightingdevices. In particular, the present disclosure is directed to lightingdevices with automatic lighting adjustment.

BACKGROUND

Task lighting provides increased illuminance for a particular activity.A task light can be configured to be wearable, such as configured to bemountable to a person's head or torso, or not, such as an overhead orwork-surface mounted light. Task lighting can be useful in any of avariety of activities, such as activities where increased illuminationof small or recessed areas is desired, such as activities performed byjewelers, gemologists, watchmakers, photographers, dentists, geologists,microelectronics designers or technicians, tattoo artists, and surgeons,etc.

In the surgical field, surgical headlamps are one of the principalsources of illumination in an operating room (OR). Surgeons rely onsurgical headlamps as a secondary source when the overhead lamps areblocked (shadowing) or in deep cavity surgeries where additionallighting is needed for visual acuity (e.g. cardiovascular, thyroid,orthopedic surgery etc.). Headlamps have the advantage of being in linewith the surgeon's field of view, delivering light in the general areawhere the surgeon is seeing.

Despite their ubiquitous use in the OR, current headlamps havesignificant limitations particularly in the area of controls. A typicalprocess of adjusting and controlling a headlamp includes, prior tosurgery, doing an initial setup of the headlamp (position, intensity,beam size, focus etc.), which can be tailored to a particular surgicalprocedure. Due to sterility concerns and because a surgeon's hands areoccupied during a surgery, this is typically the only time the surgeoncan make lighting adjustments. If a change is required, e.g., aftersurgery begins, another person may need to make the adjustment. If thesurgeon wishes to make the adjustment, e.g., by hand, the controlfeatures must be sterilized components because if the surgeon were tocome in contact with a component of the headlamp that isn't sterilized,he would need to stop surgery in order to re-sterilize beforeproceeding.

SUMMARY OF THE DISCLOSURE

In one implementation, the present disclosure is directed to a method ofcontrolling a lighting device. The method includes receiving, at aprocessor, position sensor data, the position sensor data representing aposition of at least one of a user's head and a user's eyes,determining, by the processor, whether the user is looking at a taskarea based on the position sensor data, and controlling, by theprocessor, an intensity of light emitted by the lighting device orturning the light on or off in response to determining whether the useris looking at the task area.

In some embodiments, the position sensor data is head position sensordata indicating a position of a user's head, and determining whether theuser is looking at the task area includes calculating, by the processor,an angle of the user's head from the head position sensor data, anddetermining, by the processor, whether the calculated angle is within afirst range of angles associated with the user looking at the task area.In some embodiments, the position sensor data is eye position sensordata indicating a position of a user's eyes, and determining whether theuser is looking at the task area includes determining, by the processor,whether the eye position sensor data is within a first range ofpositions associated with the user looking at the task area. In someembodiments, the first range of positions are associated with the userlooking through loupes. In some embodiments, the method further includesdetermining, by the processor, a location where the user is lookingbased on the eye position sensor data, and controlling, by theprocessor, a location of a beam of light emitted by the lighting deviceto be substantially coincident with the location where the user islooking. In some embodiments, the eye position sensor data is collectedby an eye position sensor, and the method further includes pointing thelighting device at a first one of a plurality of targets, recordingsensor data from the eye position sensor while a user is looking at thefirst one of the plurality of targets, and determining a set ofcalibrating parameters for translating a coordinate of the sensor datato a lighting device coordinate. In some embodiments, the set ofcalibration parameters are parameters of a two-dimensional linearapproximation. In some embodiments, the set of calibration parametersrepresent a translation and a rotation of a coordinate system of the eyeposition sensor to a coordinate system of the lighting device.

In another implementation, the present disclosure includes a lightingsystem. The lighting system includes a lighting device, a positionsensor, and a processor coupled to the lighting device and positionsensor configured to receive position sensor data from the positionsensor, the position sensor data representing a position of at least oneof a user's head and a user's eyes, determine whether the user islooking at a task area based on the position sensor data, and control anintensity of light emitted by the lighting device or turn the light onor off in response to determining whether the user is looking at thetask area.

In some embodiments, the position sensor is a head position sensor, theposition sensor data indicates a position of a user's head, and theprocessor is further configured to calculate an angle of the user's headfrom the position sensor data, and determine whether the calculatedangle is within a first range of angles associated with the user lookingat the task area. In some embodiments, the position sensor is an eyeposition sensor, the position sensor data indicates a position of auser's eyes, and the processor is further configured to determinewhether the position sensor data is within a first range of positionsassociated with the user looking at the task area. In some embodiments,the first range of positions are associated with the user lookingthrough loupes. In some embodiments, the processor is further configuredto determine a location where the user is looking based on the positionsensor data, and control a location of a beam of light emitted by thelighting device to be substantially coincident with the location wherethe user is looking. In some embodiments, the processor is furtherconfigured to point the lighting device at a first one of a plurality oftargets, record sensor data from the eye position sensor while a user islooking at the first one of the plurality of targets, and determine aset of calibrating parameters for translating a coordinate of the sensordata to a lighting device coordinate. In some embodiments, the set ofcalibration parameters are parameters of a two-dimensional linearapproximation. In some embodiments, the set of calibration parametersrepresent a translation and a rotation of a coordinate system of the eyeposition sensor to a coordinate system of the lighting device.

In another implementation, the present disclosure includes a method ofcontrolling a surgical lighting device. The method includes capturing,by an image capture device, an image of a surgery field, detecting, witha processor, an incision in the image, determining, with the processor,at least one property of the incision, and adjusting, by the processor,at least one setting of the surgical lighting device to illuminate theincision based on the at least one property of the incision.

In some embodiments, the at least one property of the incision includesat least one of a size, shape, and depth of the incision. In someembodiments, determining at least one property of the incision includesdetermining a size of the incision, and adjusting at least one settingof the surgical lighting device includes adjusting a beam size accordingto the determined size of the incision. In some embodiments, determiningat least one property of the incision includes determining a shape ofthe incision, and adjusting at least one setting of the surgicallighting device includes adjusting a beam shape according to thedetermined shape of the incision. In some embodiments, determining atleast one property of the incision includes determining a depth of theincision, and adjusting at least one setting of the surgical lightingdevice includes adjusting a beam focal length or intensity according tothe determined depth of the incision. In some embodiments, the methodfurther includes matching, by the processor, the detected incision witha first incision in a plurality of incisions stored in an incisiondatabase, the incision database associating each of the plurality ofincisions with a predefined surgical lighting device setting, in whichadjusting at least one setting of the surgical lighting device includesadjusting the at least one setting to correspond to the predefinedsurgical lighting device setting associated with the first incision.

In another implementation, the present disclosure includes a lightingsystem. The lighting system includes an image capture device configuredto capture an image of a surgery field, a surgical lighting device, anda processor coupled to the image capture device and the surgicallighting device configured to detect an incision in the image, determineat least one property of the incision, and adjust at least one settingof the surgical lighting device to illuminate the incision based on theat least one property of the incision.

In some embodiments, the at least one property of the incision includesat least one of a size, shape, and depth of the incision. In someembodiments, the at least one property of the incisions includes a sizeof the incision and the processor is further configured to adjust a beamsize of a light beam emitted by the surgical lighting device accordingto the determined size of the incision. In some embodiments, the atleast one property of the incisions includes a shape of the incision andthe processor is further configured to adjust a beam shape of a lightbeam emitted by the surgical lighting device according to the determinedshape of the incision. In some embodiments, the at least one property ofthe incisions includes a depth of the incision and the processor isfurther configured to adjust a beam focal length or intensity of a lightbeam emitted by the surgical lighting device according to the determineddepth of the incision. In some embodiments, the processor is furtherconfigured to match the detected incision with a first incision in aplurality of incisions stored in an incision database, the incisiondatabase associating each of the plurality of incisions with apredefined surgical lighting device setting, in which the processor isconfigured to adjust at least one setting of the surgical lightingdevice by adjusting the at least one setting to correspond to thepredefined surgical lighting device setting associated with the firstincision.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of illustrating the disclosure, the drawings showaspects of one or more embodiments of the disclosure. However, it shouldbe understood that the present disclosure is not limited to the precisearrangements and instrumentalities shown in the drawings, in which:

FIG. 1 is a perspective view of a surgical lighting device system inuse;

FIG. 2 is a functional block diagram of the system of FIG. 1;

FIG. 3 is illustrates a head position sensor coupled to acircumferential headband;

FIG. 4A is a perspective view of a surgical headlamp with eye trackingand spatial beam control in use, showing a surgeon looking at a firstlocation;

FIG. 4B is a perspective view of the surgical headlamp in use of FIG.4A, showing the surgeon looking at a second location and the surgicalheadlamp automatically adjusting the beam location to be substantiallycoincident with the second location;

FIG. 5 is a functional block diagram of an eye position sensor;

FIG. 6A shows a first incision in surgical field illuminated by lightbeam having a first size and shape for illuminating the first incision;

FIG. 6B shows a second incision in surgical field illuminated by lightbeam having a second size and shape for illuminating the secondincision;

FIG. 6C shows a third incision in surgical field illuminated by lightbeam having a third size and shape for illuminating the third incision;

FIG. 7 illustrates an incision light setting user interface;

FIG. 8 illustrates a lighting device coordinate system and an eyeposition sensor coordinate system in connection with performing acalibration procedure for a lighting device with eye tracking andspatial beam control;

FIG. 9 illustrates a process for determining calibration parameters forcalibrating an eye position sensor; and

FIG. 10 shows a diagrammatic representation of one embodiment of acomputing device that may be used for implementing lighting controlmethods of the present disclosure.

DETAILED DESCRIPTION

Aspects of the present disclosure include lighting systems andassociated controls that can provide active control of lighting devicesettings, such as on/off, color, intensity, focal length, beam location,beam size and beam shape. In some examples, control systems can providelighting system control in a sterile manner, which can be advantageousfor surgical lighting applications. In some examples, lighting systemsmay include eye tracking technology and sensor feedback for one or morelighting device settings and may be configured with depth perception andcavity or incision recognition capability through image or videoprocessing. Surgical lighting systems of the present disclosure may alsoinclude surgical lighting presets, in which a lighting device such as asurgical headlamp can be tailored and optimized for particularsurgeries. For example, beam size, beam shape, focal length, intensity,etc., may be preset ahead of time, reducing a surgeon's setup time inthe operating room. Aspects of the present disclosure also includemachine learning algorithms configured to optimize one or more lightingdevice settings, for example, based on a user's movements, headposition, duration of use, etc. Aspects of the present disclosure alsoinclude calibration procedures for calibrating an eye position sensorwith an adjustable lighting device for a particular user.

Intelligent lighting devices with automatic lighting adjustment made inaccordance with the present disclosure may be used in surgical theatersto improve sterility in a surgical environment and provide a sterilemeans of control and automation of surgical lighting, which can have apositive influence on a surgeon's ability to perform his or her tasks.Lighting devices disclosed herein can help reduce the dependence of asurgeon on other people within the operating room to make changes tosurgical lighting device settings. Benefits may also include glarereduction in the surgical field and operating room. Surgical roomstypically include a large number of metallic items that cause specularreflections and unwanted glare. By tailoring the settings of surgicallighting and enabling improved lighting control during surgery, glarecan be reduced and surgical performance improved. For example, incisionsize can be reduced and tissue trauma can also be reduced from pullingoccluding tissue out of the way. These improvements can directly lead toimproved clinical outcomes, as reducing incision size and tissue traumamay result in mitigating tissue trauma and potentially shorteningrecovery times.

FIG. 1 shows one example environment where intelligent lighting deviceswith automatic lighting adjustment of the present disclosure may beused, namely, surgical applications. FIG. 1 illustrates an examplesurgical lighting device 100 in the form of a surgical headlamp for useby a surgeon 102 to provide increased illumination of an incision 104within a surgical field 106. As discussed more fully below, lightingdevice 100 can be operably coupled to a variety of sensors and at leastone computing device that is configured to provide automated control ofone or more settings of lighting device 100.

FIG. 2 is a functional block diagram of a lighting system 200 thatincludes lighting device 100 communicatively coupled to a computingdevice 202 configured to determine one or more settings of the lightingdevice. Although FIG. 2 is discussed in connection with surgicallighting device 100 of FIG. 1, as will be appreciated by a person havingordinary skill in the art, the teachings of the present disclosure maybe applied to other task lighting systems, including overhead surgicallighting and task lighting for non-surgical applications. In theillustrated embodiment, lighting device 100 may include one or morelight sources 204. Light source 204 may be any semiconductor lightsource device, such as, for example, a light-emitting diode (LED), anorganic light-emitting diode (OLED), a polymer light-emitting diode(PLED), or a combination thereof, among others. A given solid-stateemitter may be configured to emit electromagnetic radiation (e.g.,light), for example, from the visible spectral band, the infrared (IR)spectral band, the ultraviolet (UV) spectral band, or a combinationthereof, among others. In some embodiments, a given solid-state emittermay be configured for emissions of a single correlated color temperature(CCT) (e.g., a white light-emitting semiconductor light source). In someother embodiments, a given solid-state emitter may be configured forcolor-tunable emissions; for instance, a given solid-state emitter maybe a multi-color (e.g., bi-color, tri-color, etc.) semiconductor lightsource configured for a combination of emissions, such as red-green-blue(RGB), red-green-blue-yellow (RGBY), red-green-blue-white (RGBW),dual-white, or a combination thereof, among others. In some cases, agiven solid-state emitter may be configured, for example, as ahigh-brightness semiconductor light source. In other examples, lightsource 204 may be an external light source powered by battery or mainspower and coupled to a headlamp via, e.g., a fiber optic bundle.

In some examples, settings of lighting device 100 that are controllableby computing device 202 include at least one of on/off, color,intensity, focal length, beam location, beam size and beam shape.Control of beam focal length, location, size, and shape can allow fortailoring the light generated by lighting device 100 to a particulartask. For example, for surgical lighting, beam shape, size, and focallength can be tailored to a particular incision size and depth such thatthe areas of the body below the surface of a patient's skin that arebeing operated on are sufficiently illuminated and unnecessary lightingof objects adjacent the incision, such as other portions of surgicalfield 106 and surgical objects, is avoided. Any of a variety of systemsfor adjusting one or more of beam focal length, location, size, andshape may be used. For example, spatial adjustment of the position andsize of a beam of light emitted by lighting device 100 can beaccomplished through mechanical adjustors, such as actuators,microelectromechanical systems (MEMs) or through the design of the lightengine itself. Examples include the lighting systems described in U.S.Pat. No. 9,332,619, titled “Solid-State Luminaire With Modular LightSources And Electronically Adjustable Light Beam Distribution,” and U.S.Pat. No. 9,801,260, titled, “Techniques And Graphical User Interface ForControlling Solid-State Luminaire With Electronically Adjustable LightBeam Distribution,” each of which is incorporated by reference herein inits entirety. Commercially-available lighting devices that include beamadjustment capability that may be applied to lighting devices made inaccordance with the present disclosure include micro-structured AdaptiveFront-lighting System (uAFS) devices and OMNIPOINT™ array-based LEDlighting devices, available from OSRAM, Munich, Germany.

Lighting device 100 may also include one or more position sensors 206for generating position signals for use in the control of one or moresettings of the lighting device. Position sensors 206 may include a headposition sensor 208, such as an accelerometer or gyroscope, that iscoupled to a user's head and that can be used to determine a position ofthe user's head. Position sensors 206 may also include an eye positionsensor 210 that, as described more below, may be used to determine alocation where the user is looking so that a location of a light beamgenerated by lighting device 100 may be substantially coincident withthe location the user is looking.

Lighting device 100 may also include at least one scene image capturedevice (ICD) 212 that, as described herein, can be used to capture animage of the scene being viewed by the user and that is beingilluminated by the lighting device for adjusting one or more lightingdevice settings. Scene ICD 212 may be programmed or otherwise configuredto capture or acquire images of an area such as surgical field 106 (FIG.1). For example, Scene ICD 212 may have a field of view (FOV) thatcovers substantially all of an illumination area of light sources 204.In some embodiments, the FOV of scene ICD 212 may be larger than theillumination area, which may help ensure the captured image hassufficient size to fully include the area of interest. Scene ICD 212 maybe any device configured to capture digital images, such as a stillcamera (e.g., a camera configured to capture still photographs) or avideo camera (e.g., a camera configured to capture moving imagesincluding a plurality of frames), and may be integrated, in part or inwhole, with lighting device 100 or a separate device that is distinctfrom the lighting device 100. The images can be permanently (e.g., usingnon-volatile memory) or temporarily stored (e.g., using volatilememory), depending on a given application, so that they can be analyzedby computing device 202, as further described herein. In an exampleembodiment, scene ICD 212 is a single or high resolution (megapixel)camera that captures and processes real-time video images of anillumination area of lighting device 100. Scene ICD 212 may beconfigured, for example, to acquire image data in a periodic,continuous, or on-demand manner, or a combination thereof, depending ona given application. In accordance with some embodiments, scene ICD 212can be configured to operate using light, for example, in the visiblespectrum, the infrared (IR) spectrum, or the ultraviolet (UV) spectrum,among others. Componentry of scene ICD 212 (e.g., optics assembly, imagesensor, image/video encoder) may be implemented in hardware, software,firmware, or a combination thereof.

Lighting device 100 may also include any of a variety of additionalfunctional components 214 known in the art. For example, if light source204 is an external light source, additional functional components 214may include a fiber optic bundle for transmitting light from theexternal light source to a light emitting portion of the lighting device100. Functional components 214 may also include an optical systemincluding a variable diaphragm and a lens for adjusting beam size andshape. In other examples, if light source 204 includes one or more solidstate light sources located in a headlamp, additional functionalcomponents 214 may include a modular power source, such as a waistmounted battery.

In accordance with some embodiments, computing device 202 may include amemory 220. Memory 220 can be of any suitable type (e.g., RAM and/orROM, or other suitable memory) and size, and in some cases may beimplemented with volatile memory, non-volatile memory, or a combinationthereof. Memory 220 may be utilized, for example, for processorworkspace and/or to store media, programs, applications, content, etc.,on a temporary or permanent basis. Also, memory 220 can include one ormore modules stored therein that can be accessed and executed, forexample, by processor(s) 222.

Memory 220 also may include one or more applications 224 stored therein.For example, in some cases, memory 220 may include or otherwise haveaccess to an image/video recording application or other software thatpermits image capturing/video recording using scene ICD 212, asdescribed herein. In some cases, memory 220 may include or otherwisehave access to an image/video playback application or other softwarethat permits playback/viewing of images/video captured using scene ICD212. In some embodiments, one or more applications 224 may be includedto facilitate presentation and/or operation of graphical user interfaces(UIs) such as incision light setting UI 700 described herein.Applications 224 may include an incision recognition application 226 forrecognizing an incision and/or determining a sized and/or depth of anillumination area detected in images captured by scene ICD 212, an eyetracking application 228 for receiving position data generated by eyeposition sensor 210 and determining a position of a user's eye and alocation where a user is looking, a head position application 230 fordetermining a position of a user's head, and a calibration application231 for performing a calibration procedure for calibrating lightingdevice 100. Memory 220 may also include one or more databases, such asan incision database 232 for storing information on the characteristicsof a plurality of different types of incisions and a calibrationdatabase 234 for storing calibration parameters determined during acalibration procedure performed with calibration application 203.Computing device 202 may also be programmed with one or more machinelearning algorithms for continuously or periodically adjusting thevalues of calibration parameters stored in calibration database 234, forexample, based on particular user characteristics.

Computing device 202 may also include a communication module 236, inaccordance with some embodiments. Communication module 236 may beconfigured, for example, to aid in communicatively coupling computingdevice 202 with one or more components of lighting device 100.Communication module 236 can be configured, for example, to execute anysuitable wireless communication protocol that allows fordata/information to be passed wirelessly. Computing device 202 and oneor more components of lighting device 100 can each be associated with aunique ID (e.g., IP address, MAC address, cell number, or other suchidentifier) that can be used to assist the communicative couplingtherebetween. Some example suitable wireless communication methods thatcan be implemented by communication module 236 may include: radiofrequency (RF) communications (e.g., Wi-Fi®; Bluetooth®; near fieldcommunication or NFC); IEEE 802.11 wireless local area network (WLAN)communications; infrared (IR) communications; cellular data servicecommunications; satellite Internet access communications;custom/proprietary communication protocol; and/or a combination of anyone or more thereof. In some embodiments, computing device 202 may becapable of utilizing multiple methods of wireless communication. In somesuch cases, the multiple wireless communication techniques may bepermitted to overlap in function/operation, while in some other casesthey may be exclusive of one another. In some cases a wired connection(e.g., USB, Ethernet, FireWire, or other suitable wired interfacing) mayalso or alternatively be provided between computing device 202 and theother components of system 200.

In some instances, computing device 202 may be configured to be directlycommunicatively coupled with lighting device 100. In some other cases,however, computing device 202 and lighting device 100 optionally may beindirectly communicatively coupled with one another, for example, by anintervening or otherwise intermediate network 240 for facilitating thetransfer of data between the computing device 202 and building systemcomponents. Network 240 may be any suitable communications network, andin some example cases may be a public and/or private network, such as aprivate local area network (LAN) operatively coupled to a wide areanetwork (WAN) such as the Internet. In some instances, network 240 mayinclude a wireless local area network (WLAN) (e.g., Wi-Fi® wireless datacommunication technologies). In some instances, network 240 may includeBluetooth® wireless data communication technologies. In some cases,network 240 may include supporting infrastructure and/or functionalitiessuch as a server and a service provider, but such features are notnecessary to carry out communication via network 240.

Position Sensors

As noted above, lighting device 100 may include a head position sensor208 and an eye position sensor 210. Head position sensor 208 can beconfigured to generate a position signal according to a position of auser's head, which can be used by head position application 230 executedby, e.g., computing device 202 or a separate processor (e.g., anapplication specific, dedicated, or embedded microprocessor) forcontrolling one or more settings of lighting device 100 according to aposition of the user's head. For example, in the case of examplesurgical lighting device 100 which is a surgical headlamp, head positionsensor 208 can be coupled to the headlamp for determining a position ofthe user's head. Lighting device 100 may be configured to turn on and/orhave a first intensity when the user's head is in a first position orrange of positions associated with looking at a task area, such assurgical field 106 (FIG. 1) and turn off or dim to a lower intensitywhen the user's head is not in the first position or within the firstrange of positions, such as when the user looks up from the surgicalfield. Such a feature can be beneficial to avoid unnecessarily blindingothers in the operating room with lighting device 100 when the surgeonlooks up and for conserving battery power. The first position or rangeof positions for turning lighting device 100 on can be set based on asurgeon's preference or the particular operation being performed. In thecase of surgical lighting device 100, on positions would often bepositions associated with the surgeon looking down, but could be set toother positions, e.g., for operations performed at eye level. As will beappreciated, head position sensor 208 may also be used in connectionwith overhead lights for turning on and off or adjusting the intensityof overhead task lights when the user looks towards or away from a taskarea. Whether the lighting device is an overhead task light or headlamp,head position sensor 208 may be directly coupled to a user's head suchthat the head position sensor moves with the user's head. In otherexamples, head position sensor 208 may not be physically coupled to theuser's head and may use any positioning sensor known in the art todetermine a position of the user's head, such as through the use ofinfrared light, radio waves, or acoustic waves to determine a positionof the surgeon's head.

FIG. 3 illustrates one example of a head position sensor 308 coupled toa circumferential headband 108 (see also FIG. 1) to be worn by a user tomonitor a position of the user's head. Head position sensor 308 hasthree axes—x axis 310, y axis 312 and z axis 314. A first range ofpositions defined as some reference points (x, y, z), and a range(+/−Δx, +/−Δy, +/−Δz) can be used to define when the lighting device ison. In one example, when any one of the x, y, or z values being outputby head position sensor 308 exceeds the first range of positions(x+/−Δx, y+/−Δy, z+/−Δz), the intensity of the lighting device may bereduced or the lighting device turned off. In the illustrated example,head position sensor 308 includes an accelerometer, which is configuredto characterize a lateral force of movement when the head positionsensor 308 is physically moved, and the force of gravity that the headposition sensor experiences when in a stationary position. In oneexample, the force of gravity component of the position signalsgenerated by head position sensor 308 may be used to control whetherlighting device 100 is on or off or dimmed. In one example, the force ofgravity is expressed by a 3-axes representation, into each axialcomponent x_(g), y_(g), z₉ such that √{square root over (x_(g) ²+y_(g)²+z_(g) ²)}=g, where g is the constant force of gravity.

As shown in FIG. 3, head position sensor 308 can be attached tocircumferential headband 108 and oriented relative to thecircumferential headband such that x axis 310 is substantially parallelto a longitudinal axis 316 of the circumferential headband. In such anexample, x axis 310 will be substantially horizontal, e.g.,substantially parallel to the ground when the user is standing uprightand looking straight ahead. Y axis 312 may be substantiallyperpendicular to a plane extending through longitudinal axis 316 suchthat, in use, the y axis is substantially vertical when the user isstanding upright and looking forward. With head position sensor 308oriented relative to circumferential headband 108 as shown in FIG. 3, afirst position or range of positions of head position sensor 308 forturning lighting device 100 on can be defined as a first value or rangeof values of the x_(g), y_(g) components, and/or the corresponding anglecalculated as the inverse tangent of those components. In one example,when the user will be looking down to perform a task, a first range ofvalues of the inverse tangent of

$\frac{x_{g}}{y_{g}}$for turning lighting device 100 on may be in the range of approximately−16 degrees to approximately −90 degrees, and lighting device 100 may beconfigured to turn off or dim when the inverse tangent is betweenapproximately −16 degrees and approximately 45 degrees. Head positionapplication 230 may be configured to receive position signals generatedby head position sensor 208, calculate a position of the user's headaccording to the position signals, and automatically adjust theintensity of light output by light source 204 between a first intensitywhen the user's head is in a first position or range of positions and asecond intensity when the user's head is not in the first range ofpositions.

Position sensors 206 can also include an eye position sensor 210 fordetermining a position of a user's eye. As noted above, the location ofa light beam generated by lighting device 100 may be controllable, forexample, by computing device 202. By combining eye position sensor 210with spatial beam control, lighting device can be configured toautomatically move a position of a light beam to be substantiallycoincident with a location where the user is looking. For example, FIGS.4A and 4B illustrate lighting device 100 being used by surgeon 102 andalso show an embodiment of an eye position sensor 402 incorporated intoglasses for tracking the position of the surgeon's eyes. FIG. 4Aincludes dotted line 404 illustrating a first location 406 in surgicalfield 106 where the surgeon is looking. Eye tracking application 228 canreceive position information generated by eye position sensor 402 anddetermine the position of first location 406, which can be used tocontrol a location of beam 408 so that the beam location issubstantially coincident with the first location 406. In FIG. 4B,surgeon 102 has adjusted his gaze to look at a second location 410. Eyeposition sensor 402 can detect the movement of the surgeon's eyes andcommunicate the position information to computing device 202 fordetermining second location 410 and adjusting a position of beam 408 tobe substantially coincident with the second location.

Eye position sensor 210 may also be used to control other settings oflighting device 100. For example, lighting device 100 may be configuredto turn off or dim when the user looks away from a task area. Eyeposition sensor 210 may generate eye position data and eye trackingapplication 228 may be programmed with a first range of eye positionsassociated with turning lighting device on or emitting a first intensityof light, and the eye tracking application may be configured to dim orturn off the lighting device when the eye position data is outside ofthe first range of positions. In one example, where the user uses loupes(not illustrated) to magnify a task area, eye tracking application 228may be configured to turn lighting device on when data from eye positionsensor 210 indicates the user is looking through the loupes and turn offor dim the light when the data from eye position sensor indicates theuser is not looking through the loupes.

Any of a variety of eye position sensors known in the art may be usedfor eye position sensor 210. FIG. 5 is a functional block diagram of oneexample of eye position sensor 210 and includes at least one eyeposition image capture device (ICD) 502 that records video or stillimages of a user's eye. In some examples, eye position sensor 210 mayalso include a light source 504, such as an infrared or near-infraredlight source, for creating reflections in the user's eyes that can becaptured by eye position ICD 502 to facilitate determining when a changein a position of the user's eye occurs. In some examples, eye positionsensor 210 may also include a scene ICD 506 for capturing an image ofthe scene the user is looking at, which can be used to generate a plotthat illustrates a location within the scene the user is looking. Inother examples, eye position sensor 210 may not have a separate sceneICD and may instead utilize images captured by scene ICD 212 (FIG. 2).As shown in FIGS. 4A and 4B, in one example, eye position sensor 210 maybe embodied in glasses or another structure coupled to a user's face. Inother examples, at least eye position ICD 502 and light source 504 maybe located in another location, e.g., a fixed location. One example of acommercially available eye position sensor that may be used is the TobiiPro Glasses 2 available from Tobii AB (https://www.tobiipro.com/).

Video/Image Processing for Beam Control and Light Intensity

Computing device 202 may be configured with image recognitionapplications for automatically adjusting one or more settings oflighting device 100. For example, optimal lighting device settings mayvary with a task, such as the size and depth of an area where increasedillumination from lighting device 100 is desired. In the case ofsurgical lighting, the size and depth of incisions can vary depending onthe surgery. Incisions may be as small as a 1″ in diameter (e.g.neo-natal orthopedic surgery) and range to ˜8″ to 10″ or more, e.g.,thoracic open heart surgery. Lighting device 100 can be configured toautomatically adjust one or more settings, such as color, intensity,focal length, beam size and beam shape to optimally illuminate anincision. FIGS. 6A, 6B, and 6C illustrate one example of adjusting lightbeam characteristics according to incision size, shape, and depth. FIG.6A shows a first incision 602 in surgical field 106 illuminated by lightbeam 604, where optimal settings for the light beam include a generallycircular beam shape and a beam size that is approximately equal to adiameter of an outer perimeter 606 of the incision. FIG. 6B shows asmaller incision 608. Optimum settings for the light beam 610 include agenerally circular beam shape and a beam size that is approximatelyequal to a diameter of an outer perimeter 612 of the incision. FIG. 6Cshows a third incision 614. Optimum settings for the light beam 616include a generally oval or elliptical shape and a beam size that isapproximately equal to a size of an outer perimeter 618 of the incision.In addition to beam size and shape, beam intensity and focal length mayalso be adjusted according to a depth of the incision.

Referring again to FIG. 2, scene ICD 212 may be configured to captureimages of a task space, such as surgical field 106 (FIG. 1), andcomputing device 202 can include any suitable image processingelectronics and be programmed or otherwise configured to process imagesreceived from scene ICD 212. In particular, incision recognitionapplication 226 is configured to analyze images received from scene ICD212 to identify an incision, determine optimum lighting device settingsfor illuminating the incision, and automatically control lighting device100 according to the determined settings. Using computer visionalgorithms and techniques, incision recognition application 226 canrecognize an incision. In some examples, system 200 may include aplurality of scene ICDs 212. In such instances, incision recognitionapplication 226 can be configured to analyze the different views of theimage capture devices separately or together (e.g., as a compositeimage) to determine one or more incision characteristics such as anincision size, shape, and depth.

In an example embodiment, computing device 202 receives images ofsurgical field 106 from scene ICD 212. Once received, incisionrecognition application 226 can be executed to process the images. Inone example, incision recognition application 226 can incorporatecomputer vision algorithms and techniques to process the images todetect or otherwise determine if an incision is present and thecharacteristics of the incision. In some examples, incision recognitionapplication 226 may utilize a training set of images to learn incisions.The set of images, in some embodiments, includes previous images ofincisions. The set of images can be created from the perspective of asurgeon looking down on an incision. Incision recognition application226 can learn various shapes of pixel groups that correspond toincisions, and then analyze the received images to determine if anygroup of pixels corresponds to a known incision (e.g., objectclassification using segmentation and machine learning).

In another example, a dotted line or other surface indicia may be drawnaround a perimeter of a desired area of illumination. For example, inthe example shown in FIGS. 6A-C, a dotted line is indicated at outerperimeters 606, 612, and 618. Incision recognition application 226 canbe programmed to identify dotted lines or other surface indicia insurgical field 106 to determine a size and shape of the incision, whichcan be used to determine an optimum beam size and shape for illuminatingthe incision. Incision recognition application 226 can also beprogrammed to determine a depth of an incision by analyzing imagescaptured by scene ICD 212 and adjust one or more of intensity and focallength of light, for example, increase intensity and/or focal length fordeeper incisions and decrease intensity and/or focal length forshallower incisions.

FIG. 7 illustrates an example embodiment of an incision light settinguser interface (UI) 700 that may be communicatively coupled to computingdevice 202 and/or lighting device 100, e.g., via network 240 (FIG. 2),or through a direct wired or wireless connection, for controlling one ormore settings of lighting system 200. In the illustrated example,incision light setting UI 700 may include color 702, color temperature704, beam size 706, and beam shape 708 control elements that allow auser to manually adjust the color, color temperature, beam size, andbeam shape, respectively, of light output by lighting device 100.Incision light setting UI 700 may also include a freeze button 710 forlocking a current combination of settings selected by a user to preventinadvertent further adjustment. Incision light setting UI 700 may alsoinclude an existing incision control feature 712 for selecting apreviously saved combination of lighting device settings associated witha particular incision type, and a create new incision control feature714 for saving a new combination of lighting device settings for a typeof incision. Incision light setting UI 700 may can be used by a surgeonto customize the settings of lighting device 100 to his or her specificpreferences by adjusting one or more of light color, color temperature,beam size and beam shape for a particular procedure. The surgeon canalso save a combination of settings using the create new incisioncontrol feature 714 for future use, and can then access those savedsettings at a later time via the existing incisions control feature 712.

Eye Position Sensor Calibration Procedure

FIGS. 8 and 9 illustrate aspects of one embodiment of a calibrationprocedure for calibrating eye position sensor 210 with spatial controlof the light beam generated by light source 204. Calibration application231 (FIG. 2) may be programmed to perform one or more aspects of theillustrated calibration procedure and store the calculated calibrationparameters in calibration database 234. FIG. 8 illustrates a lightingdevice coordinate system 802 with coordinates x_(L), y_(L) and an eyeposition sensor coordinate system 804 with coordinates x_(E), y_(E). Acalibration procedure can be performed to correlate the two coordinatesystems 802, 804 so that a point x_(E), y_(E) in the eye position sensorcoordinate system 804 associated with a position of a user's eyes can betranslated to a point x_(L) in the lighting device coordinate system802. Once the mapping between the two coordinate systems 802, 804 isobtained, a position of the beam of light generated by the lightingdevice can be located on substantially the same point the user islooking.

In the example illustrated in FIG. 8, lighting device is oriented andconfigured to sequentially direct a beam of light at, for example, awall 808, at a plurality of different locations, the corresponding spotsof illumination on the wall resulting in a plurality of targets 806 a,806 b, 806 c on a the wall 808. Eye position sensor 210 is operablyarranged to monitor a position of a user's eyes, for example, by placingthe eye position sensor on the user's face, and the user is instructedto look at targets 806. After a finite period of time, e.g., 3-5seconds, the lighting device moves the location of the beam of light toa different one of the calibration locations, thereby forming the nexttarget 806 on the wall, and the user is instructed to look at thetarget. FIG. 8 also illustrates data sets 810 a, 810 b, and 810 c of eyeposition data generated by eye position sensor 210. Each small circle812 (only one labeled) in each data set 810 represents a different eyeposition measurement generated by the eye position sensor and eyetracking application 228.

After acquiring eye position data 810, the calibration procedure mayinclude estimating the most likely pairs of eye position sensor data(x_(E1),y_(E1)), (x_(E2),y_(E2)), (x_(E3),y_(E3)) from the data sets 810a, 810 b, and 810 c associated with targets T₁ (806 a), T₂ (806 b), andT₃ (806 c), respectively. In one example, the most likely pairs can bedetermined using a weighted average of the prime candidates, acquired byfiltering the outliers from the datasets 810.

A two-dimensional linear approximation can be used to correlate thelighting device coordinate system 802 and the eye position sensorcoordinate system 804 as follows:x _(L)=α₁ x _(E)+β₁ u _(E) +c ₁  Eq. (1)y _(L)=α₂ x _(E)+β₂ y _(E) +c ₂  Eq. (2)in which α1, α2, β1, β2, are calibration parameters contributing to therotation of eye position sensor coordinate system 804 and c1 and c2 areparameters that account for translation of the eye position sensorcoordinate system. The calibration parameters transform x_(E), y_(E),the 2D coordinates of the gaze position in the sensor coordinate system804, to coordinates x_(L), y_(L) in lighting device coordinate system802. In one example, linear approximation requires a one-to-onecorrespondence between an instance of x_(E), y_(E) and a correspondingrespective output x_(L), y_(L). To obtain this correspondence,variability in the eye position sensor data in the allotted time ofgazing at a target can be accounted for in a variety of ways. Forexample, eye position sensor 210 generates pairs of gaze coordinates(e.g., each circle 812) and a calibration procedure may includeselecting a prime candidate x_(E), y_(E) for each target 806 a, 806 band 806 c. In the illustrated example, there are six unknowns (α1, α2,β1, β2, c1, and c2), at least three targets 806 may be used to obtain asolution for the six unknown calibration parameters.

In one example, a process of identifying prime candidates in the eyeposition sensor data sets 810 for each target, e.g., (x_(E1),y_(E1)),(x_(E2),y_(E2))(x_(E3),y_(E3)), is done by minimum mean squareestimation. For each target, the prime candidate is selected bycalculating a centroid from the corresponding gaze dataset 810 andselecting the data-point 812 that minimizes the mean square error fromthe centroid. In one example, at least one additional target 806 (e.g.,a fourth target (not illustrated)) allows the calculation of anycalibration error and may be used for rectification. In some examples,typical errors may range from about 1 to 50 pixels of scene ICD 212/506.In the event of a larger error, calibration application 231 can beprogrammed to recalibrate. In one example, recalibration arises when theuser has not focused on one or more of the target locations in theallotted time. In another example, projecting the target light on a wall808 parallel to the user can allow for the elimination of calibrationparameters α2 and β1, which would further simplify the calibrationprocess.

FIG. 9 illustrates one example process 900 for determining calibrationparameters for calibrating an eye position sensor, such as eye positionsensor 210, with a lighting device with spatial beam control, such aslighting device 100. Calibration application 231 (FIG. 2) may beprogrammed to perform one or more aspects of process 900 and store thecalculated calibration parameters in calibration database 234. In block902, a minimum number of targets such as targets 806 (FIG. 8) forcalibration procedure 900 are determined. As noted above, if thetwo-dimensional linear approximation described in equations (1) and (2)are used, then a sufficient number of data points for calculating thesix calibration parameters of equations (1) and (2) are required. Inblock 904, the lighting device can be pointed at a first one of thetargets and at block 906, the user can also look at the target. At block908, eye position sensor data can be recorded and at block 910, blocks904 through 908 can be repeated until all targets are complete, and thenat block 912, the most likely pairs of eye position sensor dataassociated with each target can be determined. And at block 914, amapping of coordinate systems can be applied to determine calibrationparameters to translate future eye position coordinates generated by theeye position sensor to coordinates in the lighting device coordinatesystem. In the example provided herein, the two dimensional linearapproximation includes calibration parameters that account fortranslation and rotation of the eye position sensor coordinate system aswell as a constant to account for errors was used. In other examples,other correlations, such as correlations that incorporate non-linearequations, three dimensions, and additional error constants, may beused.

Any one or more of the aspects and embodiments described herein may beconveniently implemented using one or more machines (e.g., one or morecomputing devices that are utilized as a user computing device for anelectronic document, one or more server devices, such as a documentserver, etc.) programmed according to the teachings of the presentspecification, as will be apparent to those of ordinary skill in thecomputer art. Appropriate software coding can readily be prepared byskilled programmers based on the teachings of the present disclosure, aswill be apparent to those of ordinary skill in the software art. Aspectsand implementations discussed above employing software and/or softwaremodules may also include appropriate hardware for assisting in theimplementation of the machine executable instructions of the softwareand/or software module.

Such software may be a computer program product that employs amachine-readable storage medium. A machine-readable storage medium maybe any medium that is capable of storing and/or encoding a sequence ofinstructions for execution by a machine (e.g., a computing device) andthat causes the machine to perform any one of the methodologies and/orembodiments described herein. Examples of a machine-readable storagemedium include, but are not limited to, a magnetic disk, an optical disc(e.g., CD, CD-R, DVD, DVD-R, etc.), a magneto-optical disk, a read-onlymemory “ROM” device, a random access memory “RAM” device, a magneticcard, an optical card, a solid-state memory device, an EPROM, an EEPROM,and any combinations thereof. A machine-readable medium, as used herein,is intended to include a single medium as well as a collection ofphysically separate media, such as, for example, a collection of compactdiscs or one or more hard disk drives in combination with a computermemory. As used herein, a machine-readable storage medium does notinclude transitory forms of signal transmission.

Such software may also include information (e.g., data) carried as adata signal on a data carrier, such as a carrier wave. For example,machine-executable information may be included as a data-carrying signalembodied in a data carrier in which the signal encodes a sequence ofinstruction, or portion thereof, for execution by a machine (e.g., acomputing device) and any related information (e.g., data structures anddata) that causes the machine to perform any one of the methodologiesand/or embodiments described herein.

Examples of a computing device include, but are not limited to, anelectronic book reading device, a computer workstation, a terminalcomputer, a server computer, a handheld device (e.g., a tablet computer,a smartphone, etc.), a web appliance, a network router, a networkswitch, a network bridge, any machine capable of executing a sequence ofinstructions that specify an action to be taken by that machine, and anycombinations thereof. In one example, a computing device may includeand/or be included in a kiosk.

FIG. 10 shows a diagrammatic representation of one embodiment of acomputing device in the form of a computer system 1000 within which aset of instructions for causing a control system, such as lightingsystem 200 of FIG. 2, to perform any one or more of the aspects and/ormethodologies of the present disclosure may be executed. It is alsocontemplated that multiple computing devices may be utilized toimplement a specially configured set of instructions for causing one ormore of the devices to perform any one or more of the aspects and/ormethodologies of the present disclosure. Computer system 1000 includes aprocessor 1004 and a memory 1008 that communicate with each other, andwith other components, via a bus 1012. Bus 1012 may include any ofseveral types of bus structures including, but not limited to, a memorybus, a memory controller, a peripheral bus, a local bus, and anycombinations thereof, using any of a variety of bus architectures.

Memory 1008 may include various components (e.g., machine-readablemedia) including, but not limited to, a random access memory component,a read only component, and any combinations thereof. In one example, abasic input/output system 1016 (BIOS), including basic routines thathelp to transfer information between elements within computer system1000, such as during start-up, may be stored in memory 1008. Memory 1008may also include (e.g., stored on one or more machine-readable media)instructions (e.g., software) 1020 embodying any one or more of theaspects and/or methodologies of the present disclosure. In anotherexample, memory 1008 may further include any number of program modulesincluding, but not limited to, an operating system, one or moreapplication programs, other program modules, program data, and anycombinations thereof.

Computer system 1000 may also include a storage device 1024. Examples ofa storage device (e.g., storage device 1024) include, but are notlimited to, a hard disk drive, a magnetic disk drive, an optical discdrive in combination with an optical medium, a solid-state memorydevice, and any combinations thereof. Storage device 1024 may beconnected to bus 1012 by an appropriate interface (not shown). Exampleinterfaces include, but are not limited to, SCSI, advanced technologyattachment (ATA), serial ATA, universal serial bus (USB), IEEE 1394(FIREWIRE), and any combinations thereof. In one example, storage device1024 (or one or more components thereof) may be removably interfacedwith computer system 1000 (e.g., via an external port connector (notshown)). Particularly, storage device 1024 and an associatedmachine-readable medium 1028 may provide nonvolatile and/or volatilestorage of machine-readable instructions, data structures, programmodules, and/or other data for computer system 1000. In one example,software 1020 may reside, completely or partially, withinmachine-readable medium 1028. In another example, software 1020 mayreside, completely or partially, within processor 1004.

Computer system 1000 may also include an input device 1032. In oneexample, a user of computer system 1000 may enter commands and/or otherinformation into computer system 1000 via input device 1032. Examples ofan input device 1032 include, but are not limited to, an alpha-numericinput device (e.g., a keyboard), a pointing device, a joystick, agamepad, an audio input device (e.g., a microphone, a voice responsesystem, etc.), a cursor control device (e.g., a mouse), a touchpad, anoptical scanner, a video capture device (e.g., a still camera, a videocamera), a touchscreen, and any combinations thereof. Input device 1032may be interfaced to bus 1012 via any of a variety of interfaces (notshown) including, but not limited to, a serial interface, a parallelinterface, a game port, a USB interface, a FIREWIRE interface, a directinterface to bus 1012, and any combinations thereof. Input device 1032may include a touch screen interface that may be a part of or separatefrom display 1036, discussed further below. Input device 1032 may beutilized as a user selection device for selecting one or more graphicalrepresentations in a graphical interface as described above.

A user may also input commands and/or other information to computersystem 1000 via storage device 1024 (e.g., a removable disk drive, aflash drive, etc.) and/or network interface device 1040. A networkinterface device, such as network interface device 1040, may be utilizedfor connecting computer system 1000 to one or more of a variety ofnetworks, such as network 1044, and one or more remote devices 1048connected thereto. Examples of a network interface device include, butare not limited to, a network interface card (e.g., a mobile networkinterface card, a LAN card), a modem, and any combination thereof.Examples of a network include, but are not limited to, a wide areanetwork (e.g., the Internet, an enterprise network), a local areanetwork (e.g., a network associated with an office, a building, a campusor other relatively small geographic space), a telephone network, a datanetwork associated with a telephone/voice provider (e.g., a mobilecommunications provider data and/or voice network), a direct connectionbetween two computing devices, and any combinations thereof. A network,such as network 1044, may employ a wired and/or a wireless mode ofcommunication. In general, any network topology may be used. Information(e.g., data, software 1020, etc.) may be communicated to and/or fromcomputer system 1000 via network interface device 1040.

Computer system 1000 may further include a video display adapter 1052for communicating a displayable image to a display device, such asdisplay device 1036. Examples of a display device include, but are notlimited to, a liquid crystal display (LCD), a cathode ray tube (CRT), aplasma display, a light emitting diode (LED) display, and anycombinations thereof. Display adapter 1052 and display device 1036 maybe utilized in combination with processor 1004 to provide graphicalrepresentations of aspects of the present disclosure. In addition to adisplay device, computer system 1000 may include one or more otherperipheral output devices including, but not limited to, an audiospeaker, a printer, and any combinations thereof. Such peripheral outputdevices may be connected to bus 1012 via a peripheral interface 1056.Examples of a peripheral interface include, but are not limited to, aserial port, a USB connection, a FIREWIRE connection, a parallelconnection, and any combinations thereof.

The foregoing has been a detailed description of illustrativeembodiments of the disclosure. It is noted that in the presentspecification and claims appended hereto, conjunctive language such asis used in the phrases “at least one of X, Y and Z” and “one or more ofX, Y, and Z,” unless specifically stated or indicated otherwise, shallbe taken to mean that each item in the conjunctive list can be presentin any number exclusive of every other item in the list or in any numberin combination with any or all other item(s) in the conjunctive list,each of which may also be present in any number. Applying this generalrule, the conjunctive phrases in the foregoing examples in which theconjunctive list consists of X, Y, and Z shall each encompass: one ormore of X; one or more of Y; one or more of Z; one or more of X and oneor more of Y; one or more of Y and one or more of Z; one or more of Xand one or more of Z; and one or more of X, one or more of Y and one ormore of Z.

Various modifications and additions can be made without departing fromthe spirit and scope of this disclosure. Features of each of the variousembodiments described above may be combined with features of otherdescribed embodiments as appropriate in order to provide a multiplicityof feature combinations in associated new embodiments. Furthermore,while the foregoing describes a number of separate embodiments, what hasbeen described herein is merely illustrative of the application of theprinciples of the present disclosure. Additionally, although particularmethods herein may be illustrated and/or described as being performed ina specific order, the ordering is highly variable within ordinary skillto achieve aspects of the present disclosure. Accordingly, thisdescription is meant to be taken only by way of example, and not tootherwise limit the scope of this disclosure.

Example embodiments have been disclosed above and illustrated in theaccompanying drawings. It will be understood by those skilled in the artthat various changes, omissions and additions may be made to that whichis specifically disclosed herein without departing from the spirit andscope of the present disclosure.

What is claimed is:
 1. A method of controlling a lighting device,comprising: receiving, at a processor, position sensor data, theposition sensor data representing a position of at least one of a user'shead and a user's eyes; determining, by the processor, whether the useris looking at a task area based on the position sensor data; andcontrolling, by the processor, an intensity of light emitted by thelighting device or turning the light on or off in response todetermining whether the user is looking at the task area, wherein thelighting device is dimmed or turned off when the user is not looking atthe task area and the lighting device is brightened or turned on toilluminate the task area when the user is looking at the task area. 2.The method of claim 1, wherein: the position sensor data is headposition sensor data indicating a position of a user's head; anddetermining whether the user is looking at the task area comprises:calculating, by the processor, an angle of the user's head from the headposition sensor data; and determining, by the processor, whether thecalculated angle is within a first range of angles associated with theuser looking at the task area.
 3. The method of claim 1, wherein: theposition sensor data is eye position sensor data indicating a positionof a user's eyes; and determining whether the user is looking at thetask area comprises: determining, by the processor, whether the eyeposition sensor data is within a first range of positions associatedwith the user looking at the task area.
 4. The method of claim 3,wherein the first range of positions are associated with the userlooking through loupes.
 5. The method of claim 3, further comprising:determining, by the processor, a location where the user is lookingbased on the eye position sensor data; and controlling, by theprocessor, a location of a beam of light emitted by the lighting deviceto be substantially coincident with the location where the user islooking.
 6. The method of claim 3, wherein the eye position sensor datais collected by an eye position sensor, and the method furthercomprises: pointing the lighting device at a first one of a plurality oftargets; recording sensor data from the eye position sensor while a useris looking at the first one of the plurality of targets; and determininga set of calibrating parameters for translating a coordinate of thesensor data to a lighting device coordinate.
 7. The method of claim 6,wherein the set of calibration parameters are parameters of atwo-dimensional linear approximation.
 8. The method of claim 6, whereinthe set of calibration parameters represent a translation and a rotationof a coordinate system of the eye position sensor to a coordinate systemof the lighting device.
 9. A lighting system, comprising: a lightingdevice; a position sensor; and a processor coupled to the lightingdevice and position sensor configured to: receive position sensor datafrom the position sensor, the position sensor data representing aposition of at least one of a user's head and a user's eyes; determinewhether the user is looking at a task area based on the position sensordata; and control an intensity of light emitted by the lighting deviceor turn the light on or off in response to determining whether the useris looking at the task area, wherein the lighting device is dimmed orturned off when the user is not looking at the task area and thelighting device is brightened or turned on to illuminate the task areawhen the user is looking at the task area.
 10. The system of claim 9,wherein: the position sensor is a head position sensor; the positionsensor data indicates a position of a user's head; and the processor isfurther configured to: calculate an angle of the user's head from theposition sensor data; and determine whether the calculated angle iswithin a first range of angles associated with the user looking at thetask area.
 11. The system of claim 9, wherein: the position sensor is aneye position sensor; the position sensor data indicates a position of auser's eyes; and the processor is further configured to determinewhether the position sensor data is within a first range of positionsassociated with the user looking at the task area.
 12. The system ofclaim 11, wherein the first range of positions are associated with theuser looking through loupes.
 13. The system of claim 11, wherein theprocessor is further configured to: determine a location where the useris looking based on the position sensor data; and control a location ofa beam of light emitted by the lighting device to be substantiallycoincident with the location where the user is looking.
 14. The systemof claim 11, wherein the processor is further configured to: point thelighting device at a first one of a plurality of targets; record sensordata from the eye position sensor while a user is looking at the firstone of the plurality of targets; and determine a set of calibratingparameters for translating a coordinate of the sensor data to a lightingdevice coordinate.
 15. The system of claim 14, wherein the set ofcalibration parameters are parameters of a two-dimensional linearapproximation.
 16. The system of claim 14, wherein the set ofcalibration parameters represent a translation and a rotation of acoordinate system of the eye position sensor to a coordinate system ofthe lighting device.